scholarly journals MgCl2-Supported Titanium Ziegler-Natta Catalyst Using Carbon Dioxide-Based Poly(propylene ether carbonate) Diols as Internal Electron Donor for 1-Butene Polymerization

Polymers ◽  
2017 ◽  
Vol 9 (11) ◽  
pp. 627
Author(s):  
Xiaopeng Cui ◽  
Qing Bai ◽  
Kai Ma ◽  
Min Yang ◽  
Binyuan Liu
2010 ◽  
Vol 115 (5) ◽  
pp. 1952-1960 ◽  
Author(s):  
K. S. Thushara ◽  
Edwin S. Gnanakumar ◽  
Renny Mathew ◽  
Ratnesh K. Jha ◽  
T. G. Ajithkumar ◽  
...  

Polymers ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 358 ◽  
Author(s):  
Zhen Zhang ◽  
Baiyu Jiang ◽  
Feng He ◽  
Zhisheng Fu ◽  
Junting Xu ◽  
...  

The kinetic behaviors of ethylene and propylene polymerizations with the same MgCl2-supported Ziegler–Natta (Z–N) catalyst containing an internal electron donor were compared. Changes of polymerization activity and active center concentration ([C*]) with time in the first 10 min were determined. Activity of ethylene polymerization was only 25% of that of propylene, and the polymerization rate (Rp) quickly decayed with time (tp) in the former system, in contrast to stable Rp in the latter. The ethylene system showed a very low [C*]/[Ti] ratio (<0.6%), in contrast to a much higher [C*]/[Ti] ratio (1.5%–4.9%) in propylene polymerization. The two systems showed noticeably different morphologies of the nascent polymer/catalyst particles, with the PP/catalyst particles being more compact and homogeneous than the PE/catalyst particles. The different kinetic behaviors of the two systems were explained by faster and more sufficient catalyst fragmentation in propylene polymerization than the ethylene system. The smaller lamellar thickness (<20 nm) in nascent polypropylene compared with the size of nanopores (15–25 nm) in the catalyst was considered the key factor for efficient catalyst fragmentation in propylene polymerization, as the PP lamellae may grow inside the nanopores and break up the catalyst particles.


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